Since all means of identification are missing why guess? The picture is so close in that you cannot see the proportions of the car to decide if it is a 25/30 or a Phantom-sized car, and all the points used to identify the coachbuilder, like the shapes of the wings (fenders), sidemounts etc are missing from view. Even the camera angle foreshortens the length of the bonnet, making a guess on the horsepower more tenuous. All Royces of this era are coachbuilt, it is necessary, therefore, to have a view of the body to ascertain who built it, it's not like looking at some pressed steel standard bodywork as fitted to lesser makes where you can recognise one of thousands of similar bodies with different grilles and boot lids.

If pushed I would say a 25/30 with Hooper bodywork, due to the shape of the small window behind the c-post, but that could be miles out.

So the whole exercise becomes pointless. As NZ says, it's obviously a car from the late 20s or early to mid 30s, but film companies couldn't care less about such anachronisms, they are all over the place. There is also a truck in this film with obviously pneumatic tyres, of a size not made until long after 1912, it's just cheap film making with low production values.